Hensuki: Are you willing to fall in love with a pervert, as long as she’s a cutie?

A calligraphy-club love letter arrives with a pair of underwear and no signature, turning Keiki's wish for a girlfriend into a raunchy school mystery among familiar girls.

Synopsis

The Anime Lad

Keiki cleans the calligraphy club room and finds a love letter addressed to him. The sender omitted her name but included a pair of underwear, narrowing nothing in a normal way. Several girls were nearby that afternoon. Keiki begins investigating. Romance has become an evidence-handling concern.

Super Eyepatch Fox

Keiki wants a girlfriend and briefly believes an unsigned club-room letter has solved the problem. The enclosed underwear changes the tone. Four girls helped clean that afternoon, giving him a finite suspect list and no sensible way to question anyone without creating a fresh disaster.

Gigguku

Keiki gets the confession he has always wanted, opens the envelope, and finds the wildest possible piece of evidence! Four girls helped clean the room that day. His romantic dream is now a school mystery with terrible interview questions and absolutely no dignified chain of custody.

Father's Basement

Subtlety never enters the club room. The mystery framing at least gives the ecchi premise a direction. Keiki has an unsigned letter, an absurd enclosure, and four possible senders from that afternoon. Solving the case would still leave the more important question of what he should say next.